1. The Field of the Invention
The present invention relates to structure for coupling syringes and other dispensing or mixing apparatus together and, more specifically, structures for threadedly coupling together syringes or other related types of devices in a secure liquid tight engagement.
2. The Prior State of the Art
Occasionally it is necessary to mix two components together before dispensing the resulting composition. For example, various adhesives and dental compositions comprise two discrete components which are independently stable but when combined interact to set in a cementitious manner. One approach to combining the discrete components is simply to dispense each of the discrete components into a third compartment where they are mixed and subsequently dispensed. In an alternative approach, the individual components are each retained in a respective syringe. The dispensing ends of the syringes are coupled together and the discrete components are passed back and forth between the syringes by advancing and retracting the corresponding plunger. The components are passed back and forth until the components are fully mixed. The mixed composition is then loaded into one of the syringes for subsequent dispensing while the later syringe is simply discarded.
A similar approach is also used in transferring material between syringes. That is, bulk quantities of materials, such as many dental compositions, are often stored in relatively large syringes. In order to mix measured amounts of the stored materials or to more easily apply the materials, a large bulk syringe is coupled with a smaller syringe such that a measured amount of the stored material can be transferred to the smaller syringe.
One approach to coupling two syringes together has been the use of discrete connectors which either press fit or threadedly engage with the nozzles of the syringes. Although such connectors are useful in many situations, such connectors often fail when it is necessary to transfer highly viscous materials between syringes, In such situations, the syringes will often separate from the connectors under the force applied to the material by the plunger. This problem is further exacerbated where the material being transferred is highly lubricious, thereby making the coupling between the syringe and the connector slippery.
It is further noted that the use of a discrete connector to couple two syringes together is undesirable in that the connector is an added expense to the system. Furthermore, such connectors are time consuming in use in that they require a separate connection to each of the syringes.
Accordingly, it is an object of the present invention to provide structure for coupling two syringes together such that material can be transferred therebetween.
Another object of the present invention is to provide structure as above which enables the syringes to be tightly secured together in a liquid tight fashion such that highly viscous and lubricious materials can be transferred between the syringes without unwanted separation or leaking of the syringes.
Finally, another object of the present invention is to provide structure as above which in one embodiment enables coupling of the two syringes without the use of a separate and discrete connector.
To achieve the foregoing objects and in accordance with the invention as described and claimed herein, a syringe system is provided. The syringe system includes a first syringe having a barrel with a tubular tip formed at the end thereof. The tubular tip has an exterior surface with a pair of spaced apart first threads outwardly projecting therefrom so as to at least particularly encircle the tubular tip. The first threads bound a first thread groove extending therebetween.
The syringe system also includes a second syringe having a barrel with a collar formed at the end thereof. The collar has an interior surface with engagement threads projecting therefrom. The collar is configured to receive the tip of the first syringe barrel such that the first threads can be selectively threadedly coupled with the engagement threads, thereby coupling the two syringes together.
The present invention also includes means mounted on the exterior surface of the tubular tip of the first syringe barrel at a location longitudinally spaced apart from the first threads for frictionally engaging the second syringe when the first syringe is threadedly coupled to the second syringe. In one embodiment, the means for frictionally engaging the second syringe comprises a pair of spaced apart second threads projecting from the exterior surface of the barrel so as to at least partially encircle the tubular barrel, the second threads being longitudinally spaced apart from the first threads.
The second threads can be substantially identical to the first threads or they can have a variety of alternative configurations. For example, the second threads can have a larger diameter and/or thickness than the first threads so as to more aggressively engage the second syringe. Furthermore, the second threads can be shifted to be slightly off-set from the first threads, rotated to a different pitch than the first threads, or sized to bound constricting or narrow grooves such that as the engagement threads couple with the second threads, the second threads aggressively bind with the engagement threads under frictional bias.
In yet another alternative embodiment of the means for frictionally engaging, the second threads can be replaced with a ridge. The ridge can either encircle the tubular tip or simply be aligned with the groove of the first threads. The ridge is configured to bias in frictional engagement with the engagement threads so as to securely lock the two syringes together in a liquid-tight fashion. The above second threads and ridge can be configured for a single or repeated coupling between the syringes.
By use of the above second threads, ridge, and other corresponding embodiments as disclosed herein, a tight friction coupling is provided between the two syringes. As a result of the secure nature of this coupling, highly viscous and lubricious materials can be repeatedly passed back and forth between the syringes without risk of accidental leaking or uncoupling of the syringes.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by the practice of the invention. The features and advantages of the invention may be realized and obtained by means of the instruments and combinations particularly pointed out in the appended claims. These and other features of the present invention will become more fully apparent from the following description and appended claims, or may be learned by the practice of the invention as set forth hereinafter.